Severe mitral annular calcification (MAC) is present in up to 24% of patients referred for surgical mitral valve replacement. Surgical mitral valve replacement remains a challenge because the debridement of MAC has been associated with very high risk for life-threatening complications (1). Transcatheter mitral valve replacement (TMVR) has been shown to be a therapeutic option for these patients (2). Nonetheless, little is known about its complications.

Among 18 patients who underwent transfemoral or transseptal TMVR for symptomatic native degenerative mitral stenosis with MAC at our center, we observed 2 cases of late valve displacement.

The procedures were performed under general anesthesia and transesophageal echocardiographic (TEE) guidance, using a 29-mm SAPIEN 3 valve (Edwards Lifesciences, Irvine, California) without complications.

The first patient was a 69-year-old man with ischemic cardiomyopathy and a left ventricular ejection fraction of 30%. Immediately after the procedure, TEE images showed good positioning and function of the prosthesis, with trace paravalvular leak (Figure 1A). The patient was discharged on day 5. He was readmitted 4 months later because of refractory heart failure. A new systolic murmur was present. Evaluation of TEE images confirmed the presence of a severe paravalvular leak due to a backward displacement of the SAPIEN 3 valve toward the left atrium (Figure 1B). The heart team’s decision was to perform a valve-in-valve TMVR. The second 29-mm SAPIEN 3 valve was placed in a more ventricular position, sealing the paravalvular leak (Figure 1C). At 1-month follow-up, the patient was asymptomatic and in New York Heart Association functional class I.

Echocardiographic Images Showing Backward Displacement of the SAPIEN 3 Prosthesis Leading to Paravalvular Regurgitation After Transcatheter Mitral Valve Replacement in the First Patient

Two-dimensional echocardiography and Doppler color flow imaging showing the final position and a trace paravalvular leak immediately after the procedure for the case 1 (A) and case 2 (D), a backward displacement with a severe paravalvular leak during the follow-up period in the Patient #1 (B) and the Patient #2 (E) and the resolution of the paravalvular mitral regurgitation after valve-in-valve transcatheter mitral valve replacement in both patients (C and F).

The second patient was an 84-year-old woman with an aortic bioprosthesis and severe left ventricular dysfunction with an ejection fraction of 35%. Immediate results were optimal, with good positioning of the prosthesis and a trace paravalvular leak (Figure 1D). The patient was discharged on day 7. At 8-month follow-up, she was referred for congestive heart failure. TEE images confirmed a backward displacement of the prosthesis and the presence of a new severe paravalvular leak (Figure 1E). Valve-in-valve TMVR using a second 29-mm SAPIEN device was performed, leading to a complete closure of the paravalvular leak (Figure 1F). At 1-month follow-up, TEE images confirmed the absence of paravalvular leaks, and the patient was asymptomatic.

The rate of delayed migration of transcatheter heart valves in patients undergoing TMVR remains unknown. The present cases highlight the severity of clinical consequences and the importance of a careful echocardiographic follow-up with a meticulous evaluation of the position of the transcatheter heart valve in patients undergoing TMVR, in particular in those with native valves. Indeed, the anchoring of the transcatheter valve in an MAC may be less strong than in a bioprosthesis or ring, depending on the amount and distribution of calcification around the mitral annulus.

The high pressure exerted by the left ventricle with high gradients between the left ventricle and left atrium might exceed the fixation forces of the prosthesis, leading to backward displacement of the prosthesis (3). Even if these patients had severe left ventricular dysfunction, delayed backward displacement of a few millimeters occurred, leading to the occurrence of severe paravalvular leaks. Even mild migration of the prosthesis prevented the protective effect of the internal and external skirts of the SAPIEN 3 device against paravalvular leaks. This complication has been treated mostly with surgical mitral valve replacement (4). Here, valve-in-valve TMVR sealed the paravalvular leak and secured the prosthesis in both cases.

The best treatment should be preventive, by using an adequate prosthesis size and high inflation pressures, pending the availability of dedicated devices in the future. Should it occur, valve-in-valve TMVR might be effective to correct a paravalvular leak and to fix the prosthesis.

Footnotes

Please note: Dr. Himbert is a proctor and consultant for Edwards Lifesciences. Dr. Vahanian has received speaking fees from Edwards Lifesciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Nguyen and Urena contributed equally to this work.